docs: def _get_upgrade_prices(self, instance_id, include_downgrade_options=True):
          """Following Method gets all the price ids related to upgrading a VS.
  
          :param int instance_id: Instance id of the VS to be upgraded
  
          :returns: list
          """
          mask = [
              'id',
              'locationGroupId',
              'categories[name,id,categoryCode]',
              'item[description,capacity,units]'
          ]
          mask = "mask[%s]" % ','.join(mask)
          return self.guest.getUpgradeItemPrices(include_downgrade_options, id=instance_id, mask=mask)